: Speaking from experience, there really wasn't any reason that the animations
: "had" to be redone for all the characters. But when it comes to
: the spartans and elites, they did need to add the ability for the fingers
: to move and I believe in the elites case, more fine tun control over the
: mandibles and eyes for the cutscenes.

: In fact if you go back to the e3 2003 demo I am pretty sure you'd see plenty
: of legacy 3p animations used, but it's been a while since I've watched it.

I also want to point out the jackal animations were likely largely redone to communicate their new more birdlike design, which was reflected in their new movements. They also seemed to want to shooting them in the arm hole to give the player a larger window to get a headshot, as part of the "dumbing down" of the game for the soccer moms.